diff --git a/SunnyUI/Controls/UIComboBox.cs b/SunnyUI/Controls/UIComboBox.cs
index daa114a1..145994d0 100644
--- a/SunnyUI/Controls/UIComboBox.cs
+++ b/SunnyUI/Controls/UIComboBox.cs
@@ -617,15 +617,21 @@ namespace Sunny.UI
 
         public void HideDropDown()
         {
-            if (!ShowFilter)
+            try
             {
-                if (ItemForm != null && ItemForm.Visible)
-                    ItemForm.Close();
+                if (!ShowFilter)
+                {
+                    if (ItemForm != null && ItemForm.Visible)
+                        ItemForm.Close();
+                }
+                else
+                {
+                    if (FilterItemForm != null && FilterItemForm.Visible)
+                        FilterItemForm.Close();
+                }
             }
-            else
+            catch
             {
-                if (FilterItemForm != null && FilterItemForm.Visible)
-                    FilterItemForm.Close();
             }
         }
 
diff --git a/SunnyUI/Controls/UINumPadTextBox.cs b/SunnyUI/Controls/UINumPadTextBox.cs
index 2f05223f..2ce19d2c 100644
--- a/SunnyUI/Controls/UINumPadTextBox.cs
+++ b/SunnyUI/Controls/UINumPadTextBox.cs
@@ -287,8 +287,14 @@ namespace Sunny.UI
 
         public void HideDropDown()
         {
-            if (NumPadForm != null && NumPadForm.Visible)
-                NumPadForm.Close();
+            try
+            {
+                if (NumPadForm != null && NumPadForm.Visible)
+                    NumPadForm.Close();
+            }
+            catch
+            {
+            }
         }
 
         /// <summary>